Bi-modal ionomers

ABSTRACT

The present invention relates to compositions and preparative process of partially or fully neutralized mixtures of carboxylate functionalized ethylene high copolymers or terpolymers (Mw between 80,000 and 500,000) with carboxylate functionalized ethylene low copolymers (Mw between 2,000 and 30,000) and organic acid salts and injection or compression molded applications such as golf ball components thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Applicant claims the benefit of priority to provisionalapplications Nos. 60/224,668 filed Aug. 11, 2000 and 60/279,023 filedMar. 27, 2001, herein incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to partially or fully neutralizedmixtures of carboxylate functionalized ethylene copolymers orterpolymers (Mw between 80,000 and 500,000) with carboxylatefunctionalized ethylene low copolymers (Mw between 2,000 and 30,000). Italso relates to the use of such ionomeric compositions in injection orcompression molded applications such as golf ball components.

[0004] 2. Description of Related Art

[0005] There is a need for highly resilient thermoplastic compositionsthat have good processibility without loss of properties or improvedproperties (improved resilience and lower stiffness) without loss ofprocessibility.

[0006] There is a need in the golf ball art for balls that have a highresilience at high speed impact such as when struck by a driver andlower resilience at low speed impact such as when struck with a putter.High resilience at high speed impact would allow longer driving distancewhile lower resilience at low speed would provide better puttingcontrol.

BRIEF SUMMARY OF THE INVENTION

[0007] The highly resilient thermoplastic compositions of this inventionprovide improved balance of properties and processibility. Also, basedon testing of spheres, they appear to be useful as compositions in golfball applications, particularly as cover and/or intermediate layermaterial or as core and/or center material or as a one-piece ball, toachieve high resilience at high impact speed and relatively lowerresilience at lower impact speed.

[0008] The thermoplastic compositions are partially or fully neutralized“bi-modal blends” of high copolymers/low copolymers. That is to say,they are melt-blends of ethylene α, β ethylenically unsaturated C₃₋₈carboxylic acid copolymers having weight average molecular weights (Mw)of about 80,000 to about 500,000 (high copolymers) with ethylene α, βethylenically unsaturated C₃₋₈ carboxylic acid low copolymers having Mwof about 2,000 to about 30,000 (low copolymers). The high copolymers maybe blends of high copolymers and the low copolymers may be blends of lowcopolymers.

[0009] It has been found that, by proper selection of the low copolymer(AC540 has been found to be particularly useful), the thermoplasticcompositions of this invention have demonstrated both enhanced meltprocessibility and enhanced heat stability. This combination of theproperty enhancements is contrasted to the reduction in heat stabilitythat would be expected with higher melt flows. These unique bi-modalionomer compositions are highly useful to the injection moldingapplications, including golf ball, foot wear, etc.

[0010] Further, with this proper selection of the low copolymer, thethermoplastic compositions of this invention are expected to haveenhanced abrasion and scuff resistance. This property enhancement,together with the other property improvements described above, would behighly useful to injection molding, films applications, including golfball, packaging films, flooring, protective coating, etc.

[0011] Preferably the weight percent high copolymer is about 50 to about95 wt. % and the weight percent low copolymer is about 5 to about 50%based on the total weight of the high copolymer and the low copolymer.Preferably about 40 to 100%, alternatively about 50 to about 85%, of theacid moieties are neutralized by alkali metal or alkyline earth metalcations.

[0012] Optionally, the composition may contain up to 100 parts by weightof organic acid salts, up to 200 parts by weight thermoplasticelastomers, up to 170 parts by weight fillers based on 100 parts byweight of the “bi-modal” ionomer of high copolymer/low copolymer blend.

[0013] The compositions described above or their blends could be appliedin broad end-uses applications, including injection moldingapplications, golf ball applications, etc. More specifically thecompositions described above are most suited for golf ball applicationssuch as the cover, intermediate layers, core, and center of 2- ormultiple-piece balls, and as thermoplastic 1-piece balls.

BRIEF DESCRIPTION OF FIGURES

[0014]FIGS. 1 through 6 are plots of coefficient of restitution versusimpact speed for the individual bi-modal ionomers and the base ionomersused in Examples 23 through 28, respectively.

[0015]FIG. 7 is a plot of the data from Examples 23 though 29 depictingthe differences in COR at the three velocities determined by subtractingthe COR of the base ionomer from the COR of the bi-modal ionomer in eachcase.

[0016]FIG. 8 is a plot of resilience versus impact speed of neat spheresbased on blends with or without the bi-modal ionomers.

[0017]FIG. 9 is a plot of the relative COR differences at differentimpact velocities between the bi-modal ionomer, i.e. BMI-1 or BMI-2,containing blends and the reference ionomer blend, i.e.ionomer-1/ionomer-2 (50:50 by weight).

DETAILED DESCRIPTION

[0018] All references disclosed herein are incorporated by reference.

[0019] “Copolymer” means polymers containing two or more differentmonomers. The terms “bipolymer” and “terpolymer” mean polymerscontaining only two and three different monomers respectively. Thephrase “copolymer of various monomers” means a copolymer whose units arederived from the various monomers.

[0020] “Low copolymer” is used herein to differentiate the lower Mwmaterials, those with Mw of about 2,000 to about 30,000, from the higherMw high copolymers, those with Mw of about 80,000 to about 500,000.

[0021] “High copolymer” is used herein to differentiate the higher Mwmaterials, those with Mw of about 80,000 to about 500,000, from thelower Mw low copolymers, those with Mw of about 2,000 to about 30,000.

[0022] “Mw” means weight average molecular weight. “Mn” means numberaverage molecular weight.

[0023] “Bi-Modal Blends” means blends of high copolymers and lowcopolymers wherein the Mw of the high copolymer and the Mw of the lowcopolymer are sufficiently different that two distinct molecular weightpeaks can be observed when measuring Mw of the blend by GPC with highresolution column.

[0024] “Ethylene (meth) acrylic acid” means ethylene acrylic acid and/orethylene methacrylic acid.

[0025] According to the present invention, ethylene α,β ethylenicallyunsaturated C₃₋₈ carboxylic acid high copolymers, particularly ethylene(meth)acrylic acid bipolymers and ethylene, alkyl (meth)acrylate,(meth)acrylic acid terpolymers, having molecular weights of about 80,000to about 500,000 are melt blended with ethylene α,β ethylenicallyunsaturated C₃₋₈ carboxylic acid low copolymers, particularly ethylene(meth)acrylic acid low copolymers (more particularly the bipolymers), ofabout 2,000 to about 30,000 by methods well known in the art.

[0026] Preferably the Mw of the high copolymers is separated from the Mwof the low copolymers sufficiently that the peaks for the highcopolymers are distinctly separated from the peaks for the lowcopolymers when the blend molecular weight distribution is determined byGPC with high resolution column. Preferably, high copolymers with lowerMw's are blended with low copolymers with lower Mw's (e.g. highcopolymers with Mw of 80,000 with low copolymers with Mw of 2,000). Thisbecomes less important as the Mw's of the high copolymers increase.

[0027] Preferably the low copolymers are present in the range of about 5to about 50 weight percent based on the total weight of the highcopolymers and the low copolymers in the blend.

[0028] Preferably the high copolymers and low copolymers are partiallyor fully neutralized by alkali metal or alkyline earth metal cations.Preferably, about 40 to about 100%, alternatively about 50 to about 85%,alternatively about 50 to about 90%, alternatively about 60 to about 80%of the acid moieties in the high copolymers and low copolymers areneutralized. Cations are lithium*, sodium*, potassium, magnesium*,calcium, barium, lead, tin, or zinc* (*=preferred), or a combination ofsuch cations.

[0029] Neutralization can be effected by first making an ionomer of thehigh copolymer and/or of the low copolymer and then melt-blending them.To achieve desired higher or full neutralization the resulting blend ofionomers can be further neutralized. Preferably the high copolymers andlow copolymers are melt-blended and then neutralized in situ. In thiscase desired higher or full neutralization can be achieved in one step.

[0030] Optionally, the composition may contain up to 100 parts by weightof organic acid salts, up to 200 parts by weight thermoplasticelastomers, up to 170 parts by weight fillers based on 100 parts byweight of the “bi-modal” ionomer of the high copolymer/low copolymerblend. Other additives such as stabilizers and processing aids can beincluded.

[0031] The components of the blends of the present invention are morefully described below.

High Copolymers

[0032] The high copolymers of this invention are preferably ‘direct’acid copolymers (as opposed to grafted copolymers) having an Mw of about80,000 to about 500,000. Preferably they have polydispersities (Mw/Mn)of about 1 to about 15.

[0033] They are preferably alpha olefin, particularly ethylene, /C₃₋₈α,β ethylenically unsaturated carboxylic acid, particularly acrylic andmethacrylic acid, copolymers. They may optionally contain a thirdsoftening monomer. By “softening”, it is meant that the polymer is madeless crystalline. Suitable “softening” comonomers are monomers selectedfrom alkyl acrylate and alkyl methacrylate, wherein the alkyl groupshave from 1-12 carbon atoms, and vinyl acetate.

[0034] The ethylene acid copolymers can be described as an E/X/Ycopolymers where E is ethylene, X is the α,β ethylenically unsaturatedcarboxylic acid, and Y is a softening comonomer. X is preferably presentin 2-30 (preferably 5-25, most preferably 8-20) wt. % of the polymer,and Y is preferably present in 0-35 (alternatively 3-25 or 10-25) wt. %of the polymer.

[0035] The ethylene-acid copolymers with high levels of acid (X) aredifficult to prepare in continuous polymerizers because ofmonomer-polymer phase separation. This difficulty can be avoided howeverby use of “co-solvent technology” as described in U.S. Pat. No.5,028,674 which is incorporated herein by reference or by employingsomewhat higher pressures than those at which copolymers with lower acidcan be prepared.

[0036] Specific acid-copolymers include ethylene/(meth) acrylic acidbipolymers. They also include ethylene/(meth) acrylic acid/n-butyl(meth) acrylate, ethylene/(meth) acrylic acid/iso-butyl (meth) acrylate,ethylene/(meth) acrylic acid/methyl (meth) acrylate, and ethylene/(meth)acrylic acid/ethyl (meth) acrylate terpolymers.

[0037] Examples of high copolymers and their molecular weights are shownin the following table. Mn Mw Polydispersity Composition/MI (10³⁾ (10³⁾(Mw/Mn) E/23.5nBA/9MAA/25MI 26.6 176.5 6.6 E/15MAA/60MI 17.6 112.4 6.4E/4MAA/3MI 31.7 365.5 11.5 E/5.8AA/1.5MI 31.5 162.1 5.1 E/9AA/10MI 24.3186.4 7.7 E/10MAA/500MI 16.0 84.0 5.3 E/10MAA/35MI 19.6 160.8 8.2

Low Copolymers

[0038] The low copolymers of this invention are preferably ‘direct’ acidcopolymers having an Mw of about 2,000 to about 30,000. Preferably theyhave polydispersities (Mw/Mn) of about 1 to about 10. They arepreferably alpha olefin, particularly ethylene, /C₃₋₈α,β ethylenicallyunsaturated carboxylic acid, particularly acrylic and methacrylic acid,copolymers. Preferably the acid moiety in these copolymers is about 3 toabout 25 (preferably 5-15, most preferably 5-10) wt. % of the polymer.

[0039] Often these low copolymers are referred to as acid copolymerwaxes available from Allied Signal (e.g., Allied wax AC143 believed tobe an ethylene/16-18% acrylic acid copolymer with a number averagemolecular weight of 2,040, and others indicated in the following tablewith their molecular weights). Mn Mw Polydispersity Composition/MI (10³)(10³) (Mw/Mn) AC540 E/5AA/575 cps 4.3 7.5 1.7 Brookfield @140C** AC580E/10AA/650 cps 4.8 26.0 5.4 Brookfield @140 C** AC5120 E/15AA/650 cps3.0 5.2 1.7 Brookfield @140 C**

Ionomers

[0040] Ionomers of the high copolymers and of the low copolymers whenmade separately can be made by methods well known in the art. The degreeof neutralization and the acid level should be selected so that theresulting ionomers of the high copolymers and the ionomers of the lowcopolymers remain melt processible.

[0041] The bi-modal ionomers of high copolymer/low copolymer blends canbe made by melt blending the melt processible ionomers separately madeand then optionally further neutralizing with same or different cationsto achieve desired higher or full neutralization of the resulting blendof ionomers. Preferably the non-neutralized high copolymers and lowcopolymers are melt-blended and then neutralized in situ. In this casedesired higher or full neutralization can be achieved in one step.

[0042] In either case, the neutralization can be effected by alkalimetal or alkaline earth metal cations. Such cations are lithium*,sodium*, potassium, magnesium*, calcium, barium, lead, tin, or zinc*(*=preferred), or a combination of such cations. Preferably the acidmoieties in the resulting bi-modal ionomer of the high copolymers andlow copolymers are partially or fully neutralized to a level of about 40to about 100%, alternatively about 50 to about 85%, alternatively about50 to about 90%, alternatively about 60 to about 80%.

Organic Acid Salts

[0043] The salt of organic acid of the present invention comprises thesalts, particularly the barium, lithium, sodium, zinc, bismuth,chromium, cobalt, copper, potassium, strontium, titanium, tungsten,magnesium or calcium salts, of fatty acids, particularly stearic,behenic, erucic, oleic, linoleic, Preferably, the fatty acid salt isselected to have the lowest volatility. It is chosen so as to maximizeCOR while minimizing stiffness or compression, which has often beencalled “PGA Compression” in the golf ball art.

Thermoplastic Elastomers

[0044] The thermoplastic polymer component of the invention is selectedfrom copolyetheresters, copolyetheramides, elastomeric polyolefins,styrene diene block copolymers and thermoplastic polyurethanes, theseclasses of polymers being well known in the art.

[0045] The copolyetheresters are discussed in detail in patents such asU.S. Pat. Nos. 3,651,014; 3,766,146; and 3,763,109. They are comprisedof a multiplicity of recurring long chain units and short chain unitsjoined head-to-tail through ester linkages, the long chain units beingrepresented by the formula

[0046] and the short chain units being represented by the

[0047] where G is a divalent radical remaining after the removal ofterminal hydroxyl groups from a poly (alkylene oxide) glycol having amolecular weight of about 400-6,000 and a carbon to oxygen ratio ofabout 2.0-4.3; R is a divalent radical remaining after removal ofcarboxyl groups from a dicarboxylic acid having a molecular weight lessthan about 300; and D is a divalent radical remaining after removal ofhydroxyl groups from a diol having a molecular weight less than about250; provided said short chain ester units amount to about 15-95 percentby weight of said copolyetherester. The preferred copolyetheresterpolymers are those where the polyether segment is obtained bypolymerization of tetrahydrofuran and the polyester segment is obtainedby polymerization of tetramethylene glycol and phthalic acid. Of course,the more polyether units incorporated into the copolyetherester, thesofter the polymer. For purposes of the invention, the molar ether:esterratio can vary from 90:10 to 10:90, preferably 80:20 to 60:40; and theshore D hardness is less than 70, preferably less than about 40.

[0048] The copolyetheramides are also well known in the art as describedin U.S. Pat. No. 4,331,786, for example. They are comprised of a linearand regular chain of rigid polyamide segments and flexible polyethersegments, as represented by the general formula

[0049] wherein PA is a linear saturated aliphatic polyamide sequenceformed from a lactam or amino acid having a hydrocarbon chain containing4 to 14 carbon atoms or from an aliphatic C₆-C₉ diamine, in the presenceof a chain-limiting aliphatic carboxylic diacid having 4-20 carbonatoms; said polyamide having an average molecular weight between 300 and15,000; and PE is a polyoxyalkylene sequence formed from linear orbranched aliphatic polyoxyalkylene glycols, mixtures thereof orcopolyethers derived therefrom said polyoxyalkylene glycols having amolecular weight of less than or equal to 6,000 and n indicates asufficient number of repeating units so that said polyetheramidecopolymer has an intrinsic viscosity of from about 0.8 to about 2.05.The preparation of these polyetheramides comprises the step of reactinga dicarboxylic polyamide, the COOH groups of which are located at thechain ends, with a polyoxyalkylene glycol hydroxylated at the chainends, in the presence of a catalyst such as a tetra-alkyl ortho-titinatehaving the general formula Ti(OR)₄, wherein R is a linear branchedaliphatic hydrocarbon radical having 1 to 24 carbon atoms. Again, themore polyether units incorporated into the copolyetheramide, the softerthe polymer. The ether:amide ratios are as described above for theether:ester ratios, as is the shore D hardness.

[0050] The elastomeric polyolefins are polymers composed of ethylene andhigher primary olefins such as propylene, hexene, octene and optionally1,4-hexadiene and or ethylidene norbornene or norbornadiene. Theelastomeric polyolefins can be functionalized with maleic anhydride.

[0051] Thermoplastic polyurethanes are linear or slightly chain branchedpolymers consisting of hard blocks and soft elastomeric blocks. They areproduced by reacting soft hydroxy terminated elastomeric polyethers orpolyesters with diisocyanates such as methylene diisocyanate (MDI) ortoluene diisocyanate(TDI). These polymers can be chain extended withglycols, diamines, diacids or amino alcohols. The reaction products ofthe isocyanates and the alcohols are called urethanes and these blocksare relatively hard and high melting. These hard high melting blocks areresponsible for the thermoplastic nature of the polyurethanes.

[0052] Block styrene diene copolymers are composed of polystyrene unitsand polydiene units. The polydiene units are derived from polybutadiene,polyisoprene units or copolymers of these two. In the case of thecopolymer it is possible to hydrogenate the polyolefin to give saturatedrubbery backbone segments. These materials are usually referred to asSBS, SIS or SEBS thermoplastic elastomers and they can also befunctionalized with maleic anhydride.

Fillers

[0053] The optional filler component of the subject invention is chosento impart additional density to the bi-modal ionomers or blends of themwith other materials. Preferred densities depend on the application. Ingolf balls, they will include densities in the range starting with thedensity of unfilled polymer to 1.8 gm/cc. Generally, the filler will beinorganic having a density greater than about 4 gm/cc, preferablygreater than 5 gm/cc, and will be present in amounts between 0 and about60 wt. % based on the total weight of the composition. Examples ofuseful fillers include zinc oxide, barium sulfate, lead silicate andtungsten carbide, tin oxide, as well as the other well knowncorresponding salts and oxides thereof. It is preferred that the fillermaterials be non-reactive or almost non-reactive with the polymercomponents described above when the ionomers are less than completelyneutralized. If the ionomers are fully neutralized, reactive fillers maybe used. Zinc Oxide grades, such as Zinc Oxide, grade XX503R availablefrom Zinc Corporation of America, that do not react with any free acidto cause cross-linking and a drop in Ml are preferred, particularly whenthe ionomer is not fully neutralized.

Other Components

[0054] Other optional additives include titanium dioxide which is usedas a whitening agent or filler; other pigments, optical brighteners;surfactants; processing aids; etc.

Uses of Composition in Golf Balls

[0055] The bi-modal ionomers of this invention are useful in combinationwith other materials in specific combinations which, in large part, willbe dependent upon the application. The bi-modal ionomers may besubstituted for one or more materials taught in the art at the levelstaught in the art for use in covers, cores, centers, intermediate layersin multi-layered golf balls, or one-piece golf balls. Sufficient fillerscan be added to one or more components of the golf ball to adjust theweight of the golf ball to a level meeting the limits set by thegolfer's governing authority. See, for example, U.S. Pat. Nos.4,274,637; 4,264,075; 4,323,247; 4,337,947, 4,398,000; 4,526,375;4,567,219; 4,674,751; 4,884,814; 4,911,451; 4,984,804; 4,986,545;5,000,459; 5,068,151; 5,098,105; 5,120,791; 5,155,157; 5,197,740;5,222,739; 5,253,871; 5,298,571; 5,321,089; 5,328,959; 5,330,837;5,338,038; 5,338,610; 5,359,000; 5,368,304; 5,810,678; 5,971,870;5,971,871; 5,971,872; 5,973,046; 5,810,678; 5,873,796; 5,757,483;5,567,772; 5,976,443; 6,018,003; 6,096,830; and WO 99/48569.

Three-piece Golf Ball

[0056] As used herein, the term “three-piece ball” refers to a golf ballcomprising a center, a traditional elastomeric winding wound around thecenter, and a cover made from any traditional golf ball cover materialsuch as Surlyn® ionomer resin, balata rubber or thermoset /thermoplasticpolyurethanes and the like. These three-piece golf balls aremanufactured by well known techniques as described in U.S. Pat. No.4,846,910 for example. The bi-modal ionomer may be used in the cover orthe center of such balls in combination with other materials typicallyused in these components.

Two-piece Golf Ball

[0057] As used herein, the term “two-piece ball” refers to a golf ballcomprising a core and a cover made from any traditional golf ball covermaterial as discussed above. These two-piece balls are manufactured byfirst molding the core from a thermoset or thermoplastic composition,positioning these preformed cores in injection molding cavities usingretractable pins, then injection molding the cover material around thecores. Alternatively, covers can be produced by compression moldingcover material over the cores. The bi-modal ionomer may be used in thecover or the core of such balls alone or in combination with othermaterials typically used in these components.

Multi-Layer Golf Ball

[0058] As used herein, the term “multi-layer ball” refers to a golf ballcomprising a core, a cover made from any traditional golf ball covermaterial, and one or more mantles between the core and the cover. Thesemulti-layer balls are manufactured by first molding or making the core,typically compression or injection molding a mantle over the core andthen compression or injection molding a cover over the mantle. Thebi-modal ionomer may be used in the cover, the one or more mantles orthe core of such balls alone or in combination with other materialstypically used in these components.

One-piece Golf Ball

[0059] As used herein, the term “one-piece ball” refers to a golf ballmolded in toto from a thermoplastic composition, i.e., not havingelastomeric windings nor a cover. The one-piece molded ball will have atraditional dimple pattern and may be coated with a urethane lacquer orbe painted for appearance purposes, but such a coating and/or paintingwill not affect the performance characteristics of the ball. Theseone-piece balls are manufactured by direct injection molding techniquesor by compression molding techniques. The bi-modal ionomer may be usedin such balls in combination with other materials typically used inthese balls.

EXAMPLES AND COMPARATIVE EXAMPLES

[0060] The resins used in the examples were as follows: Mn* Mw*Polydispersity* Composition/MI (E3) (E3) (Mw/Mn) AC540 E/5AA/500 cpsBrookfield 4.3 7.5 1.7 @140 C** AC580 E/10AA/650 cps 4.8 26.0 5.4Brookfield @140 C** AC5120 E/15AA/650 cps 3.0 5.2 1.7 Brookfield @140C** HCP 1 E/23.5nBA/9MAA/25MI 26.6 176.5 6.6 HCP 2 E/8.3AA/17nBAIonomer-1 E/23.5nBA/9MAA, 51% Mg neutralized/1.1MI Ionomer-2 E/19MAA,37% Na neutralized/2.6MI Ionomer-3 E/11MAA, 37% Na neutralized/10MIIonomer-4 E/11MAA, 57% Zn neutralized/5.2MI Ionomer-5 E/15MAA, 53% Znneutralized/5.0MI Ionomer-6 E/15MAA, 51% Na neutralized/4.5MI

EXAMPLES 1-6

[0061] Blends of E/9MAA/23.5 nBA (HCP 1) and E/10AA (AC580) at 90:10(Example 1) and 80:20 (Example 2) ratios were neutralized on a singlescrew extruder with a Mg(OH)₂ concentrate into bi-modal ionomers withthe level of neutralization indicated in the following table. Theionomers of Example 1 and Example 2 together with reference Ionomer-1(Comparative Example 3) were injection molded into spheres and testedfor the golf ball properties. Improved COR's are measured for thebi-modal ionomers over the reference. When bi-modal ionomer of Example 1was further modified with Magnesium Stearate, dramatic propertyenhancements were achieved (Examples 4, 5 and 6). Ex. 1 Ex. 2 Comp. Ex.3 E/MAA/nBA, wt % 90 80 100 E/AA, wt % 10 20 0 Nominal Neut., % 70 75 51MI at 190° C. 1 1 1.1 PGA compression 86 90 58 Drop Rebound, % 59.8 56.356.6 COR-125 0.671 0.670 0.644 COR-180 0.628 0.628 0.596 Ex. 4 Ex. 5 Ex.6 Ex. 1 Bi-modal 85 70 60 ionomer, wt. % MgSt.,w % 15 30 40 MI at 190°C. 1.5 1.6 2.5 PGA compression 85 83 91 Drop Rebound, % 68.3 75.2 77.1COR-125 0.728 0.761 0.773 COR-180 0.678 0.703 0.718

EXAMPLES 7-12

[0062] A pellet blend of 90 wt. % Ionomer-2 and 10 wt. % E/1 5AA(AC5120) was melt blended and neutralized in the presence of a specificamount of Na₂CO₃ concentrate to a nominal neutralization level of 60% ina twin screw extruder to achieve the bi-modal ionomer (BMI-2). A pelletblend of 90 wt. % Ionomer-1 and 10 wt. % E/10AA (AC580) was melt blendedand neutralized in the presence of a specific amount of Mg(OH)₂concentrate to a nominal neutralization level of 70% in a twin screwextruder to achieve the bi-modal ionomer (BMI-1). Ionomer blends werethen prepared by melt blending on a twin screw extruder at 50:50 ratiothe bi-modal ionomers, i.e. BMI-2, BMI-1 and the conventional ionomers,i.e. Ionomer-2 and Ionomer-1. The base ionomers and blends depicted inthe table were injection molded into spheres and tested for the golfball properties. The resilience enhancement of the blends containing thebi-modal ionomers was clearly illustrated. Comp. Comp. Comp. Ex. 7 Ex. 8Ex. 9 Ex. 10 Ex. 11 Ex. 3 Ex. 12 BMI-2, wt % 50 50 — — 100 — BMI-1, wt %50 — 50 — — — Ionomer-2 — — 50 50 — 100 Ionomer-1 — 50 — 50 — 100 — MI0.6 0.6 NA NA 0.6 1.1 2.0 Neat Sphere Property PGA 130 125 132 126 15058 158 compression Drop 67.3 66.7 66.7 64.6 76 56.6 80.3 Rebound, %COR-125 0.707 0.697 0.689 0.671 0.740 0.644 0.750 COR-180 0.659 0.6510.640 0.621 0.692 0.596 0.693

EXAMPLES 13-18

[0063] Bimodal ionomers based on Na and Zn ionomers containing 11% MAA,i.e. Ionomer-3 and Ionomer-4, and E/10AA at 90:10 ratio were prepared onthe twin screw extruder under the blending/neutralization conditionssimilar to the above examples using a Na₂CO₃ concentrate or a ZnOconcentrate. The base ionomers and the bi-modal ionomers were injectionmolded into spheres and tested for the golf ball properties. Thebi-modal ionomers and their blends showed lower PGA compression andimproved COR. Com. Comp. Comp. Ex. 13 Ex. 14 Ex. 15 Ex. 16 Ex. 17 Ex. 18BMI-3 100 50 BMI-4 100 50 Ionomer-3 100 50 Ionomer-4 100 50 NominalNeut, 75 75 37 57 75 47 % MI 1 2 10 5 1.8 NA PGA Comp. 130 134 146 139134 146 Drop Rebound, 67.7 59 64.5 60.4 66.3 66.7 % COR-125 0.702 0.6210.649 0.615 0.691 0.669 COR-180 0.660 0.580 0.601 0.569 0.651 0.622

EXAMPLES 19-22

[0064] Blend of E/8.3AA/17 nBA (HCP 2) and E/10AA (AC580) at 90:10weight ratio was neutralized on a single screw extruder with a Mg(OH)₂concentrate into a bi-modal ionomer with 2MI and a nominalneutralization level of 63% (Examples 20). A reference (ComparativeExample 19) was also prepared under the similar conditions to a nominalneutralization level of 53% with HCP 2 alone. The ionomers are injectionmolded into spheres and tested for the golf ball properties. ImprovedCOR's are measured for the bi-modal ionomers over the reference. Whenbi-modal ionomers of Example 20 were further modified with MgSt.(Examples 21 and 22) dramatic property enhancements were achieved. Comp.Ex. 19 Ex. 20 Ex. 21 Ex. 22 MgSt. Mod., w % 0 0 15 40 MI 2 2 1.9 1.3 PGAComp. 108 111 108 108 Drop Rebound, 60.9 61.9 69.2 79.4 % COR-125 0.6730.676 0.728 0.794 COR-180 0.631 0.636 0.686 0.745

EXAMPLES 23-29

[0065] Bi-modal ionomers of this invention achieve performanceimprovement over the conventional base ionomer references in therelative relationship between resilience and impact speed, i.e. highrelative resilience at high impact speed and lower relative resilienceat low impact speed when compared with conventional ionomercounterparts. This performance combination is highly desirable in thegolf ball application to enable greater driving distance and betterputting control. COR Difference between BM Surlyn and Ref. SurlynExample 23 ft/s 125 ft/s 180 ft/s 23 BMI-3-Ionomer-3 0.020 0.053 0.05924 BMI-4-Ionomer-4 −0.009 0.006 0.011 25 BMI-5***-Ionomer-5 −0.008 0.0160.023 26 BMI-6****-Ionomer-6 −0.022 −0.010 0.001 27 BMI-2-Ionomer-2−0.024 −0.010 −0.001 28 BMI-1/20*-Ionomer-1 −0.002 0.026 0.032 29BMI-1/10**-Ionomer-1 0.021 0.027 0.032

[0066]FIGS. 1 through 6 are plots of coefficient of restitution versusimpact speed for the individual bi-modal ionomers and the base ionomersused in Examples 23 through 28, respectively. The impact speed of 23feet/second was achieved by a drop rebound test (dropping sphere from aheight of 100 inches onto a hard, rigid surface such as a thick steelplate or a stone block). The COR was then calculated from the impactvelocities based on the drop height and the rebound height measured.COR's at 125 and 180 feet/second speeds were measured by firing thesphere from an air cannon at a velocity determined by the air pressure.The outbound velocity generally employed is between 125 to 180feet/second. The ball strikes a steel plate positioned three feet awayfrom the point where outbound velocity is determined, and reboundsthrough a speed-monitoring device. The return velocity divided by theoutbound velocity is the COR.

[0067]FIG. 7 is a plot of the data in the table. It is a plot of thedifferences in COR at the three velocities determined by subtracting theCOR of the base ionomer from the COR of the bi-modal ionomer in eachcase.

[0068]FIG. 8 is a plot of resilience versus impact speed of neat spheresbased on blends with or without the bi-modal ionomers. The bi-modalstiff ionomer and blends property characterization is provided in thefollowing table. Bi-modal Stiff Ionomer and Blends PropertyCharacterization Ionomer-2 100 50 50 Ionomer-1 50 50 BMI-2 100 50 50BMI-1 50 50 MI, g/10 min 2 0.6 NA 0.6 NA 0.6 Neat Sphere Property PGACompression 158 150 126 125 132 130 Drop Rebound, % 80.3 76 64.6 66.766.7 67.3 COR-23 (Calc) 0.896 0.872 0.804 0.817 0.817 0.820 COR-125 0.750.74 0.671 0.697 0.689 0.707 COR-180 0.693 0.792 0.621 0.651 0.64 0.659

[0069]FIG. 9 is a plot of the relative COR differences at differentimpact velocities between the bi-modal ionomer, i.e. BMI-1 or BMI-2,containing blends and the reference ionomer blend, i.e.ionomer-1/ionomer-2 (50:50 by weight). While the bi-modal ionomercontaining blends exhibit higher COR at higher impact velocities, theyexhibit comparable COR at 23 ft/second to allow good putting control, incombination with long drive distance. 23 ft/sec 125 ft/sec 180 ft/secCOR at Different Impact Speeds Ionomer-2/Ionomer-1 0.804 0.671 0.621BMI-2/Ionomer-1 0.817 0.697 0.651 Ionomer-2/BMI-1 0.817 0.689 0.64BMI-2/BMI-1 0.82 0.707 0.659 COR Difference Relative toIonomer-2/Ionomer-1 Blend BMI-2/Ionomer-1 0.013 0.026 0.03Ionomer-2/BMI-1 0.013 0.018 0.019 BMI-2/BMI-1 0.016 0.036 0.038

EXAMPLES 30 to 33

[0070] Bi-modal ionomers of this invention achieve performanceimprovement over the conventional base ionomer references in the heatstability, as measured by the resistance to deformation at the elevatedtemperature and under stress. E/9MAA/23.5nBA (HCP 1) was partiallyneutralized (about 51%) with Mg(OH)₂ concentrate on a single screwextruder and was subsequently blended with E/5AA (AC540) at 90:10(Example 30) and 85:15 (Example 31) ratios and further neutralized withMg(OH)₂ concentrate to maintain approximately 51% neutralization.

[0071] E/9MAA/23.5nBA (HPC 1) was also partially neutralized (about 51%)with ZnO concentrate on a single screw extruder and subsequently blendedwith E/5AA (AC540) at 90:10 (Example 32) and 85:15 (Example 33) ratios.

[0072] The bi-modal ionomers consistently demonstrated lowerdeformations than the conventional base ionomer references aftersubjecting to 70° C. and 1 Newton force for 1400 minutes reflectingenhanced resistance to heat induced deformation, i.e. heat stability.This performance enhancement is highly desirable in the golf ballapplication to enable ball stability when stored in hot environmentunder load. Ex. Ex. Comp. Ex. Ex. Comp. Ex. 1 30 31 Ex. 3 32 33 Ex. 34**MI 1 1.8 2.7 0.95 0.48 0.77 0.28 % Deform.* 17.3 10.2 9.9 22.1 15 9.720.6

What is claimed is:
 1. A composition comprising a thermoplasticcomposition that is melt processible consisting essentially of (a) E/X/Ycopolymers where E is ethylene, X is a C3 to C8 α,β ethylenicallyunsaturated carboxylic acid, and Y is a softening comonomer, preferablyselected from alkyl acrylate, and alkyl methacrylate, wherein the alkylgroups have from 1-8 carbon atoms, or ionomers of the E/X/Y copolymerswherein X is about 2-30 wt. % of the E/X/Y copolymer, and Y is 0 toabout 35 wt. % of the E/X/Y copolymer, and (b) 5-50 wt. % based on(a)+(b) of one or more E/(M)AA copolymers having 3-25 wt. % (M)AA orsalts thereof, wherein the acid of (a) and of (b) is partially to highlyneutralized to greater than 40%.
 2. The composition of claim 1 whereinthe E/X/Y copolymers have the Mw in the range of 80,000 to 300,000, andthe E/(M)AA copolymers having the Mw between 2,000 and 30,000.
 3. Thecomposition of claim 2 wherein the E/(M)AA copolymer content ranges from5 to 30 wt. % based on (a)+(b).
 4. The composition of claim 3 wherein Yis about 10 to 30 wt. % of the E/X/Y copolymer.
 5. The composition ofclaim 3 wherein X is about 2 to 20 wt. % of the E/X/Y copolymer and Y isabout 15 to 35 wt. % of the E/X/Y copolymer.
 6. The composition of claim3 wherein greater than 50% of all the acid of (a) and of (b) isneutralized.
 7. A composition comprising a thermoplastic compositionthat is melt processible consisting essentially of (a) the compositionof claim 1, and (b) 5-50 wt. % based on (a)+(b) of one or morealiphatic, mono-functional organic acids having fewer than 30 carbonatoms or salt thereof, wherein greater than 80% of all the acid of (a)and of (b) is neutralized.
 8. The composition of claim 7 wherein asufficient amount of filler is added to adjust the density to a valueranging between that of said composition without filler and 1.8 gm/cc.9. A composition comprising a thermoplastic composition that is meltprocessible consisting essentially of (a) the composition of claim 2,and (b) one or more aliphatic, mono-functional organic acids havingfewer than 30 carbon atoms or salt thereof at 5 to 50 wt. % of (a)+(b),wherein greater than 90% of all the acid of (a) and of (b) isneutralized.
 10. A composition comprising a thermoplastic compositionthat is melt processible consisting essentially of (a) the compositionof claim 5, and (b) one or more aliphatic, mono-functional organic acidshaving fewer than 30 carbon atoms or salt thereof at 5 to 50 wt. % of(a)+(b), wherein greater than 90% of all the acid of (a) and of (b) isneutralized.
 11. The composition of claim 10 wherein greater than 100%of all the acid of (a) and of (b) is neutralized
 12. The composition ofclaim 11 wherein the organic acid is one or more C10 to C22 organicacids.
 13. A composition comprising (a) the composition of claim 7, (b)1-30 wt. % based on (a)+(b) of thermoplastic elastomeric resin selectedfrom copolyetheramides, copolyetheresters, elastomeric polymerolefins,block polystyrene polydiene copolymers, and thermoplastic urethanes. 14.The composition of claim 13 wherein a sufficient amount of filler isadded to adjust the density to a value ranging between that of saidcomposition without filler and 1.8 gm/cc.
 15. A process to make a meltprocessible bi-modal ionomer comprising the step of (a) melt blending anE/X/Y copolymer or a melt processible ionomer thereof with an E/(M)AA orsalt thereof, and (b) concurrently or subsequently adding sufficientcation source to neutralize greater than 40% of all the acid moieties ofE/X/Y copolymer or ionomer thereof and the E/(M)AA or salt thereof
 16. Aprocess to make a melt processible bi-modal ionomer comprising the stepof (a) melt blending concurrently or sequentially an E/X/Y copolymer ora melt processible ionomer thereof with an E/(M)AA or salt thereof, andan organic acid or a salt thereof, and (b) concurrently or subsequentlyadding sufficient cation source to neutralize greater than 80% of allthe acid moieties of E/X/Y copolymer or ionomer thereof, the E/(M)AA orsalt thereof, and the organic acid or salt thereof.
 17. The process ofclaim 16 wherein sufficient cation source is added to neutralize about95% or higher of the acid moieties.
 18. The process of claim 16 whereinsufficient cation source is added to neutralize at least about 100% ofthe acid moieties.
 19. The cover of a golf ball comprising thecomposition of claims 1, or 7, wherein sufficient filler is added (toone or more components of the golf ball) to adjust the weight of thegolf ball to a level meeting the limits set by the golfer's governingauthority.
 20. An intermediate layer in a multi-layer golf ballcomprising the composition of claim 1, 7, or 13, wherein sufficientfiller is added (to one or more components of the golf ball) to adjustthe weight of the golf ball to a level meeting the limits set by thegolfer's governing authority.
 21. A core or part of a core of a two- ormultiple-piece golf ball or a center of a three-piece golf ballcomprising the composition of claim 1, 7, or 13, wherein sufficientfiller is added (to one or more components of the golf ball) to adjustthe weight of the golf ball to a level meeting the limits set by thegolfer's governing authority.
 22. A one-piece golf ball comprising thecomposition of claim 1, 7, or 13, wherein sufficient filler is added toadjust the weight of the golf ball to a level meeting the limits set bythe golfer's governing authority.